GB2071307A

GB2071307A - Fan-assisted storage heater

Info

Publication number: GB2071307A
Application number: GB8105070A
Authority: GB
Original assignee: TUGOFINSA SA
Current assignee: TUGOFINSA SA
Priority date: 1980-02-21
Filing date: 1981-02-18
Publication date: 1981-09-16
Also published as: GB2071307B

Abstract

A fan-assisted storage heater for supplying heated air (e.g. to a room) comprises a cabinet 1 containing heat storage material (e.g. concrete blocks) 2 incorporating heating elements (e.g. electric elements) 3. Ambient air is drawn into a chamber 5 (e.g. by two electric fans 17, Fig. 2 at the ends thereof) and circulates through an air- heating duct 6 formed e.g. between the material 2 and heat insulation 4, to an outlet chamber 7 and thence into the room to be heated. In a bypass passage 9 between the chambers 5 and 7 is a baffle 10 which may be thermostatically controlled. Additional air at room temperature from outside the cabinet is admitted to the outlet chamber 7 via inlets 11 and 15 to mix with and cool the heated air in said chamber, thereby preventing the emission of air which is too hot. <IMAGE>

Description

SPECIFICATION Fan assisted storage heater The invention relates to a fan-assisted storage heater. Such storage heaters have electric heating elements which take cheap-rate electricity at night to heat a heat store of thermal storage material.

During the day heat is extracted and vented to the room to be heated by being circulated in ducting around the heat store with the assistance of an electric fan.

In a particular kind of storage heater with which the present invention is concerned the fan is situated at the base of the heater cabinet and blows air up through ducting which passes the air around the heat store and down to emerge from a grille at the base of the front face of the cabinet.

When the heat store is fully charged the temperature of the emerging air can be too hot for safety. To alleviate this problem and give a temperature control facility there is provided an outlet chamber at the base of the heater between the end of the ducting and the grille, and a by-pass passage to admit cold air directly from the fan to the outlet chamber. The by-pass passage is provided with a controllable baffle which allows adjustment of the amount of cold air which is bypassed and mixed with the hot air. The baffle may be controlled automatically in response to temperature.

With such a heater, if the baffle is opened to cool the emerging air sufficiently when the heat store is fully charged, then most of the air from the fan is by-passed and the quantity of air available for circulation around the heat store for heat extraction is limited. Thus, rate of flow of air at an acceptable temperature is limited by the fan arrangement in spite of the fact that there is sufficient stored heat to warm a larger volume of air per unit time. The present invention seeks to provide an improvement.

According to the invention there is provided a fan-assisted storage heater comprising a cabinet; a heat store of thermal storage material in the cabinet; heating elements to heat the heat store; ducting which conveys air through the heat store from an inlet at the bottom to an outlet at the bottom; an electric fan for forcing air into the ducting inlet; an outlet chamber at the ducting outlet; a by-pass passage to admit air directly from the fan to the outlet chamber; and a baffle in the by-pass passage to control the amount of air bypassed; wherein the lower part of the cabinet is provided with one or more inlet vents for admitting cold air directly from the exterior of the cabinet; and means for directing airflow in the outlet chamber so as to induce air via the inlet vent or vents to be mixed with and cool the heated air.

The inlet vent or vents are preferably arranged so that air from the by-pass passage assists the induction of air through the inlet vent or vents.

Preferably, additional by-pass for air from the fan to the outlet chamber is provided by a series of jets which give high velocity low-volume air streams directed to assist in inducing air via the inlet vent or vents.

The invention will further be described with reference to the accompanying drawings, of which Figure 1 is a schematic side elevation of a fanassisted storage heater in accordance with the invention; and Figure 2 is a perspective view of the fan box of the heater.

Referring to Figure 1 there is shown a storage heater having a cabinet 1 which encloses a heat store 2 made of concrete blocks. Within the heat store are electric heating elements 3 and thermal insulation is provided at 4. A fan box 5 at the base of the cabinet draws ambient air into the cabinet and directs it around ducting 6 where is extracts heat from the store and the air finally emerges to an outlet chamber 7 and then through a grille 8 to the room. A by-pass passage 9 has a baffle 10 which is thermostatically controlled. When the baffle is open, or partly open, the by-pass passage receives cold air from the fan chamber and the cold air mixes with the hot air from the ducting. The emerging air is consequently cooled.

The invention provides a vent 11 which allows air to be drawn into the outlet chamber from beneath the heater. A baffle 1 2 assists in directing the hot air from the ducting in the direction of the arrows 13 and this deflection helps in drawing air through the inlet vent. Also, the direction of the by-pass air from passage 9 assists in drawing air in via the inlet vent.

Additionally, the fan box is provided with spaced holes 14 which act as jets to direct a narrow stream of relatively fast moving air into the outlet chamber. This action also assists in the induction of air via the inlet vent. A further modification consists in the provision of another inlet vent 1 5 with a baffle 16, this arrangement allowing the introduction of further cold air-as indicated by the arrow. Air is drawn in from beneath the baffle 12 and the incoming air is directed thereby in the direction of the air-stream in the outlet chamber.

Referring to Figure 2 the fan box is shown in greater detail. Air is drawn in axially by two fans 1 7 at the ends of the box; the air is directed into the box and thence out through the main outlet at 18. The by-pass passage 9 and the jet holes 14 are shown also.

1. A fan-assisted storage heater comprising a cabinet; a heat store of thermal storage material in the cabinet; heating elements to heat the heat store; ducting which conveys air through the heat store from an inlet at the bottom to an outlet at the bottom; an electric fan for forcing air into the ducting inlet; an outlet chamber at the ducting outlet; a by-pass passage to admit air directly from the fan to the outlet chamber; and a baffle in the by-pass passage to control the amount of air bypassed: wherein the lower part of the cabinet is provided with one or more inlet vents for

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fan assisted storage heater The invention relates to a fan-assisted storage heater. Such storage heaters have electric heating elements which take cheap-rate electricity at night to heat a heat store of thermal storage material. During the day heat is extracted and vented to the room to be heated by being circulated in ducting around the heat store with the assistance of an electric fan. In a particular kind of storage heater with which the present invention is concerned the fan is situated at the base of the heater cabinet and blows air up through ducting which passes the air around the heat store and down to emerge from a grille at the base of the front face of the cabinet. When the heat store is fully charged the temperature of the emerging air can be too hot for safety. To alleviate this problem and give a temperature control facility there is provided an outlet chamber at the base of the heater between the end of the ducting and the grille, and a by-pass passage to admit cold air directly from the fan to the outlet chamber. The by-pass passage is provided with a controllable baffle which allows adjustment of the amount of cold air which is bypassed and mixed with the hot air. The baffle may be controlled automatically in response to temperature. With such a heater, if the baffle is opened to cool the emerging air sufficiently when the heat store is fully charged, then most of the air from the fan is by-passed and the quantity of air available for circulation around the heat store for heat extraction is limited. Thus, rate of flow of air at an acceptable temperature is limited by the fan arrangement in spite of the fact that there is sufficient stored heat to warm a larger volume of air per unit time. The present invention seeks to provide an improvement. According to the invention there is provided a fan-assisted storage heater comprising a cabinet; a heat store of thermal storage material in the cabinet; heating elements to heat the heat store; ducting which conveys air through the heat store from an inlet at the bottom to an outlet at the bottom; an electric fan for forcing air into the ducting inlet; an outlet chamber at the ducting outlet; a by-pass passage to admit air directly from the fan to the outlet chamber; and a baffle in the by-pass passage to control the amount of air bypassed; wherein the lower part of the cabinet is provided with one or more inlet vents for admitting cold air directly from the exterior of the cabinet; and means for directing airflow in the outlet chamber so as to induce air via the inlet vent or vents to be mixed with and cool the heated air. The inlet vent or vents are preferably arranged so that air from the by-pass passage assists the induction of air through the inlet vent or vents. Preferably, additional by-pass for air from the fan to the outlet chamber is provided by a series of jets which give high velocity low-volume air streams directed to assist in inducing air via the inlet vent or vents. The invention will further be described with reference to the accompanying drawings, of which Figure 1 is a schematic side elevation of a fanassisted storage heater in accordance with the invention; and Figure 2 is a perspective view of the fan box of the heater. Referring to Figure 1 there is shown a storage heater having a cabinet 1 which encloses a heat store 2 made of concrete blocks. Within the heat store are electric heating elements 3 and thermal insulation is provided at 4. A fan box 5 at the base of the cabinet draws ambient air into the cabinet and directs it around ducting 6 where is extracts heat from the store and the air finally emerges to an outlet chamber 7 and then through a grille 8 to the room. A by-pass passage 9 has a baffle 10 which is thermostatically controlled. When the baffle is open, or partly open, the by-pass passage receives cold air from the fan chamber and the cold air mixes with the hot air from the ducting. The emerging air is consequently cooled. The invention provides a vent 11 which allows air to be drawn into the outlet chamber from beneath the heater. A baffle 1 2 assists in directing the hot air from the ducting in the direction of the arrows 13 and this deflection helps in drawing air through the inlet vent. Also, the direction of the by-pass air from passage 9 assists in drawing air in via the inlet vent. Additionally, the fan box is provided with spaced holes 14 which act as jets to direct a narrow stream of relatively fast moving air into the outlet chamber. This action also assists in the induction of air via the inlet vent. A further modification consists in the provision of another inlet vent 1 5 with a baffle 16, this arrangement allowing the introduction of further cold air-as indicated by the arrow. Air is drawn in from beneath the baffle 12 and the incoming air is directed thereby in the direction of the air-stream in the outlet chamber. Referring to Figure 2 the fan box is shown in greater detail. Air is drawn in axially by two fans 1 7 at the ends of the box; the air is directed into the box and thence out through the main outlet at 18. The by-pass passage 9 and the jet holes 14 are shown also. CLAIMS

1. A fan-assisted storage heater comprising a cabinet; a heat store of thermal storage material in the cabinet; heating elements to heat the heat store; ducting which conveys air through the heat store from an inlet at the bottom to an outlet at the bottom; an electric fan for forcing air into the ducting inlet; an outlet chamber at the ducting outlet; a by-pass passage to admit air directly from the fan to the outlet chamber; and a baffle in the by-pass passage to control the amount of air bypassed: wherein the lower part of the cabinet is provided with one or more inlet vents for admitting cold air directly from the exterior of the cabinet; and means for directing air flow in the outlet chamber so as to induce air via the inlet vent or vents to be mixed with and cool the heated air.

2. A fan-assisted storage heater as claimed in claim 1 wherein air emerging from the ducting is deflected so as to cause induction of air into the inlet vent or vents.

3. A fan-assisted storage heater as claimed in claim 1 or claim 2 wherein air emerging from the by-pass passage is directed so as to cause induction or air into the inlet vent or vents.

4. A fan-assisted storage heater as claimed in any of the preceding claims wherein additional bypass jets for air from the fan to the outlet chamber are provided, air from the jets providing high velocity low-volume air-streams directed so as to cause induction of air into the inlet vent or vents.

5. A fan-assisted storage heater as claimed in any of the preceding claims wherein there is an inlet vent which admits air upwardly from beneath the cabinet into a transverse air-stream in the outlet chamber.

6. A fan-assisted storage heater as claimed in any of the preceding claims wherein there is an inlet vent which admits air from beneath the cabinet under a baffle which directs the incoming air in the direction of the air-stream in the outlet chamber.

7. A fan-assisted storage heater substantially as hereinbefore described with reference to the accompanying drawings.